FGF-19 is a member of the fibroblast growth factor (FGF) family. FGF family members possess broad mitogenic and cell survival activities, and are involved in a variety of biological processes, including embryonic development, cell growth, morphogenesis, tissue repair, tumor growth and invasion. FGF-19 is a specific ligand for FGF R4. Similarly, another FGF family member, FGF-7 (KGF), only activates KGF R, the IIIb isoform of FGF R2. During chick embryogenesis, FGF-19 has been shown to act synergistically with Wnt-8c to initiate inner ear development.